Zip Packages - AWS Lambda Web Adapter User Guide

AWS Lambda Web Adapter works with AWS managed Lambda runtimes via Lambda Layers.

Setup Steps

1. Attach the Lambda Web Adapter Layer

AWS Commercial Regions

Architecture	Layer ARN
x86_64	`arn:aws:lambda:${AWS::Region}:753240598075:layer:LambdaAdapterLayerX86:27`
arm64	`arn:aws:lambda:${AWS::Region}:753240598075:layer:LambdaAdapterLayerArm64:27`

AWS China Regions

Region	Architecture	Layer ARN
cn-north-1 (Beijing)	x86_64	`arn:aws-cn:lambda:cn-north-1:041581134020:layer:LambdaAdapterLayerX86:27`
cn-northwest-1 (Ningxia)	x86_64	`arn:aws-cn:lambda:cn-northwest-1:069767869989:layer:LambdaAdapterLayerX86:27`

2. Set the Exec Wrapper

Configure the Lambda environment variable:

AWS_LAMBDA_EXEC_WRAPPER=/opt/bootstrap

3. Set the Function Handler

Set your function handler to your web application's startup script, e.g. run.sh.

SAM Template Example

Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Runtime: nodejs20.x
      Handler: run.sh
      Layers:
        - !Sub arn:aws:lambda:${AWS::Region}:753240598075:layer:LambdaAdapterLayerX86:27
      Environment:
        Variables:
          AWS_LAMBDA_EXEC_WRAPPER: /opt/bootstrap
          AWS_LWA_PORT: 7000

Windows Users

If you create your Zip package on Windows, your startup script (e.g. run.sh) must meet two requirements to work in the Lambda Linux runtime:

Use LF line endings — Windows defaults to CRLF (\r\n), which causes /bin/sh to fail with cannot execute: required file not found.
Set Unix file permissions to 755 — Zip files created on Windows don't preserve Unix execute permissions.

Most zip utilities on Windows don't handle Unix permissions. You can work around this by using WSL, a build script that sets permissions explicitly, or a tool like 7-Zip with the -mcu flag. See #611 for more details.

For a complete working example, see the Express.js in Zip example.